The present invention relates to a technique of manufacturing a semiconductor integrated circuit device, and particularly relates to the technique of chemical mechanical polishing (CMP) applied to the principal plane on the patterned side of a patterned semiconductor wafer, that is, a wafer for manufacturing a semiconductor integrated circuit (hereinafter called a wafer).
Recently, methods of manufacturing a semiconductor device, that is, a semiconductor integrated circuit device wherein irregularities on the principal plane on the patterned side of a patterned wafer are flattened by chemical mechanical polishing have been proposed. The technique for flattening irregularities on the principal plane on the patterned side of a patterned wafer by chemical mechanical polishing has the following problems, compared with the technique for flattening irregularities on the principal plane of a wafer before patterning by chemical mechanical polishing. A first problem is that the quantity of polishing equivalent to the quantity removed by processing is extremely limited. For example, the quantity in which a wafer before patterning is polished is several tens .mu.m, while the quantity in which a patterned wafer is polished is approximately 0.5 .mu.m. A second problem is that the flatness of the principal plane to be polished on the patterned side of a patterned wafer is by far indistinct, compared with that of a wafer before patterning. It is difficult to uniformly perform chemical mechanical polishing of irregularities on the overall principal plane on the patterned side of a patterned wafer in consideration of these problems.
For an example in which the technique for polishing a patterned wafer chemically and mechanically to conquer this difficulty is disclosed, there are Japanese published unexamined patent applications No. Hei 5(1993)-74749, Hei 6(1994)-15563 and No. Hei 5(1993)-69310. Any technique disclosed in these examples is based upon a principle that the overall principal plane to be polished on the patterned side is uniformly rubbed on the surface of an abrasive by pressing the patterned wafer by an elastic body in which pressure fluid is sealed.